Pressure-relief regulator for slide-valves



(No Model.)

W. P. GARRISON.

PRESSURE RELIEEREGULATOR FOR SLIDE VALVESi No. 497,020.

Patented May 9, 1893.

as co. Pncnuuma, WASHINGTON. u. c.

UNTTnD STaTns PATENT Orrrcn.

WILLIAM F. GARRISON, OF BROOKLYN, NEV YORK. i

PRESSURE-RELIEF REGULATOR FOR SLIDE-VALVES.

SPECIFICATION forming part of Letters Patent No. 497,020, dated May 9,1893. Application filed July 12,1892. Serial No.- 4s9i771. (No model.)

To all whom it may concern:

Be it known that I, WILLIAM F. GARRIsoN, of Brooklyn, in the county ofKings and State of New York, have invented a new and useful Improvementin PressureeRelief Regulators for Slide-Valves, of which the followingis a specification.

My invention relates to an improvement in pressure relief regulators forslide valves in which provision is made for reducing the pressure in thevalve chamber to a point where it will be suliicient to keep the valveseated but not sufiicient to cause it to press heavily upon its seat,while at the sametime the pressure within the cylinder maybe raised toany desired degree.

I have chosen to illustrate my invention a pump for moving gaseousbodies in which the inlet and discharge ports and the passagewaysleading from the valve chamber to the cylinder are located at one sideof the valve chamber and underneath the valve. The same principle aswill be observed from the following explanation might however be appliedin other arrangements of pumps and where the pressure instead of beingproduced by the action of the piston within the cylinder is employed todrive the piston within the cylinder as in the steam engine, which wouldbe in effeet a simple reversal of the form which I have herein chosen.

In the accompanying drawings: Figure 1 represents a verticallongitudinal section of the pump and Fig. 2 is an end elevation of thesame.

The cylinder is denoted by A,its piston by B and piston rod by h. Thecylinder is surmounted by a plate D which forms the bottom of the valvechamber 0 and through which passage ways d, d lead from the oppositeends of the cylinderAto the valve chamber 0. A discharge port is denotedby F and communicates with the valve chamber intermediate of thepassage-ways d, d and leads to the discharge or compression chamber fthrough a self -acting valve G. Inlet ports E, E are formed in the plateD and communicate with the interior of the valve chamber G upon oppositesides of the passageways cl, d. A slide valve I is located in the valvechamber 0 and is provided with a port t" for opening communicationbetween the inlet ports E, E

and the passage-ways (Z, d and with a central cove 'i for openingcommunication between the passageways d, d and the discharge port F. Apassageway, in the present instance a pipe I-I, leads from thecompression or discharge chamber f to the valve chamber 0 and saidpassage-way is intercepted by a reducing pressure valve J of any wellknown or approved form.

In the form which I have chosen, the pump is used either as a vacuum orcompression pump, the piston 13 being operated by a source of power notshown. As it moves back and forth within the cylinder A, it forces thefluid from that side toward which it is moving out through thepassage-way at that end of the cylinder toward which it is movingthrough the cove i in the valve and the discharge port F and valve Ginto the discharge or compression chamber f and thence through adischarge pipe K to the point where the compressed fluid is to beutilized or, in the case of its use as a vacuum, it may be dischargedinto the open air. That portion of the cylinder A in which a vacuum isformed by the movement of the piston B is filled with fluid through theone or the other of the inlet ports E, E, port qlin the valve and theone or the other of the passage-ways d, 01' leading to the opposite endsof the cylinder. There is therefore a filling of the cylinder A upon oneside of the piston B and the discharge of the fluid from the other sideof the piston B at each stroke of the piston and this may take placewithout any communication between the cylinder and the valve chamberexterior to the valve itself. It is desirable, however, that thereshould be sufficient pressure upon the valve I to keep it seated andthat this pressure should be exerted by the fluid within the valvechamber exterior to the valve rather than by any arrangement of guidesor weights in order that the pressure upon the valve may be varied tosuit the different pressures under which the pump may be operatingwithout producing undue pressure upon thevalve and the wear resultingtherefrom. To this end, I provide a passage-way I-I leading from thedischarge or compression chamber f to the valve chamber O exterior tothe valve with a reducing pressure valve J which may be set to anydesired degree of tension so that while sufficient ICO pressure istransmitted from the chamber f of a passage-way in communication withthe to the valve chamber to hold the valve to its valve chamber exteriorto the valve and with seat, there may not be transmitted the full thehigh pressure chamber and a reducing pressure Within the chamber f orenough to pressure valve interposed in said passage-way 5 overburden thevalve and cause it to unduly for regulating the pressure within thevalve cut away its seat. chamber exterior to the valve, substantiallyWhat I claim is as set forth. The combination with a cylinder, a valveWVILLIAM F. GARRISON. chamber, a slide valve Within the chamber, aWitnesses: 10 high pressure chamber and the inlet and dis- FREDK.HAYNES, charge ports under the control of the valve, I. B. DECKER.

